Shaped body and process of preparing the same



Dec. 28, 1943. A. MENGER ETAL 2,337,915

SHAPED BODY AND PROCESS OF PREPARING THE SAME Filed Aug. 26, 1941Mala/m6 fit/"27110 was gtl ornqy at 'a raised temperature. This processof preparing pressed plates by us- Pltented Dec. 28, 19 43 UNITED STATESPATENT OFFICE},-

SHAIED BODY AND PROCESS OF. PREPAR- ING THE SAME Adolf Menger and EugenBock, Krefeld-Uerdingen, Germany; vested in the Alien Property CustodianApplication August 26, 1941, Serial No. 408,346

In Germany April 30, 1940 I 10 Claims. (01. 18-48) It is known thatpressed plates may be prepared by mixing comminuted porous materialsespecially comminuted wood such as wood' dust or shavings, furthermoreleather, fibrous materials or the like with a liquid binding agent, ifdesired, while simultaneously adding a non-porous substance such asstone powder and, thereupon, pressing the mixture obtained, if desired,

ing porous materials has the disadvantage that during the mixingoperation aconsiderable portion of the liquid binding agent penetratesinto the interior of the particles'of the comminuted material and,consequently, cannot take part in the binding of the particles togetherwhich during pressing takesplace at the surface of said particles. Inorder to obtain plates of satisfactory strength it is, therefore,necessary to use such large quantities of liquid binding agentthat 20the weight of the plates is undesirably high for many purposes. I

The object of this invention is a process of preparing shaped or moldedarticles, in particular pressed plates, which avoids the abovedrawbacks.

According to the process of the present invention, which is illustratedby the flow sheet in the accompanying drawing, the liquid binding agentis mixed in the form of foam with the porous a0 material and the mixtureis then pressed. It is surprising that the structure of the foam is notdestroyed during 'the mixing thereof with the comminuted material. Onthe contrary, the surface of the particles is coated with a layer offoam 5 which is relatively stable and is absorbed but little by theparticles so that practically almost the entire binding agent isavailable for binding the I particles of material when the masses arepressed together. Consequently the present process re- 40 quires muchsmaller quantities of binding agent than used in the processes hithertoknown while, at the same time, shaped or molded articles much lighter inweight may be obtained.

In order to obtain shaped or molded articles of satisfactory strength itis necessary, according to the process of the present invention, toshape the particles by pressure at such temperatures and under suchpressures that the foam structure of the binding agent is destroyed to aconsiderable extent. These conditions may be readily ascertained foreach particular case by a simple test.

The foam may be prepared according in a known manner by finelydispersing gases, especially air, in the liquid or dissolved gluingsubstance. It is advantageous to add foam-forming or foam-promotingagents such as, for instance,

- albuminous substances, saponins or the like or other natural orartificial organic compounds of high molecular weight. The gas may alsobe produced in known manner, in the solution of the gluing agent itself,for instance, by addition of carbonates or bicarbonates from whichcarbonic acid is split off by heating or by adding an acid.

For the process of the present invention there may be used any of thebinding agents usual in the art and, especially synthetic bindingagents, such as, for instanc, those having as their base urea-aldehydeor phenol-aldehyde condensation products. Natural binding agents may beused such as glue from hides, bone glue, dextrin or the like.

According to the process of th present invention there may be obtained,for example, in addition to pressed plates, .blocks, beams of any crosssection, for instance, masts, T-girders or the like, chair legs, lampstands, doorknobs, containers and casings or thelike.

The following examples serve to illustrate the invention but they arenot intended tolimit it thereto; the parts are by weight.

Example 1 2,5 parts ofbutylnaphthalene sulfonic acid, 1 part of ammoniumchloride, 5 parts of urea and 25 parts of an ammoniacal solution ofcasein of 5% strength are added to parts of an aqueous I solution of 65%strength of a condensation product from urea and formaldehyde. Into thismixture air is introduced in a finely divided state by means of arapidly agitated stirring device until the volume of the glue-batch hastrebled.

, 50 parts of this foamy glue mixture are well mixed with 1000 parts ofwood shavings. The material thus obtained is brought into a press or apress mould and pressed for 12 hours at 20 C. whereby a pressed plate ofremarkable strength is obtained.

Example 2 100 parts of a foamy glue mixture according to Example 1 arewell mixed with 1000 parts of comminuted wood waste obtained in themanufacture of ply wood. The material thus obtained is brought into apress or a press mould and pressed for 12 hours at 20 C. the structureof the foam being destroyed by the action of the pressure and thesubsequent binding operation.

In this way a beam of remarkable strength is obtained.

We claim: 1. 'A process of preparing molded articles which comprisesmixing a liquid binding agent in the form of foam with comminuted porousmaterial and subjecting the mixture to a pressure surficient to form thearticle and substantially completely destroy the foam structure of thebinding agent.

2. A process of preparing molded articles which comprises mixing aliquid binding agent in the form of foam, the base of which is asynthetic resin, with comminuted porous material and sub--,

jecting the mixture to a pressure suflicient to form the article andsubstantially completely destroy the foam structure of the bindingagent.

3. A process of preparing molded articles which comprises mixing aliquid binding agent in the form of foam, the base of which is aurea-a1- dehyde condensation product, with comminuted porous materialand subjecting the mixture to a pressure suificient to form the articleand substantially completely destroy the foam structure of the bindingagent.

4. A process of preparing molded articles which comprises mixing aliquid binding agent in the form of foam, the base of which is aureaformaldehyde condensation product, with comminuted porous materialand subjecting the mixture to a pressure sufficient to form the articleand substantially completely destroy the foam structure of the bindingagent.

. 5. A process of preparing molded articles which 'comprisesmixingaliquid binding'agent in the form of foam the base of which is aurea-formaldehyde condensation product, with comminuted wood' andsubjecting the mixture to a pressure sufllcient to form the article andsubstantially completely destroy the foam structure of the bindingagent.

6. A molded article obtained in accordance with the process of claim 1.

'7. A molded artlcle obtained in accordance with the process of claim 2.

8. A- molded article obtained in accordance withthe process of claim 3.

9. A molded article obtained in accordance with the process of claim 4.c -10. A molded article obtained in accordance with the process ofclaim5.

ADQLF MENGER. EUGEN BOC'K.

